feat(plat/imx/imx8m/imx8mm): enlarge BL33 (U-boot) size in FIP
feat(plat/imx/imx8m/imx8mm): enlarge BL33 (U-boot) size in FIP

When enabling U-boot with UEFI and secure boot, the size of U-boot
becomes more than 1MB. So we enlarge BL33 to 2MB.

Signed-off-by: Ying-Chun Liu (PaulLiu) <d85c815cccd4e7eb2bf30ecc174aeb0eef10ab96@debian.org>
Change-Id: I9d9d24132bb1ec17ef6080dc72e93c7f531c97b5

achingupta/arm-trusted-firmware,achingupta/arm-trusted-firmware